Telescopic tube



July 23, 1963 L. P. FORTIN ETA]. 3,098,669

TELESCOPIC TUBE Filed April 17, 1961 IN VE N TORS L 001's Phi/[gas FOR TIN E'uyne LEN/[0X BY I W PATENT AGENT assignors t sixty-six and two-thirds to Ernest Beaupre, Montreal, Quebec, Canada, and thirty-three and onethird to said Fortin Filed Apr. 17, 1961, Ser. No. 103,530 4- Claims. (Cl. 287-58) The present invention relates to a telescopic tube having improved means for adjustably locking the tube sections and which may be applied to a plurality of uses, such as a handle for a shovel, broom and the like implement, or as telescopic legs for tripods and the like.

The main object of the present invention resides in the provision of a telescopic tube of the character described in which the tube sections are telescopically engaged and can be locked in any length adjusted position by the simple rotation of one section relative to the other through a very limited angle, and can be released or unlocked by rotation in the opposite direction.

Yet another important object of the present invention resides in the provision of a telescopic tube of the character described in which the tube sections are very firm-1y locked together by a comparatively small rotational force exerted on one of the tube sections.

Still another important object of the present invention resides in the provision of a telescopic tube of the character described including a conical expander integrally provided with a polygonal shaped 'head and engaging a tube section of special cross-sectional shape in order to prevent rotation of the expander and yet provide a tube section which can be extruded for minimum cost, which requires a minim-um of material and which yet provides a smooth outer surface so that said section can be readily and comfortably gasped by one hand.

Yet another object of the invention resides in the provision of a telescopic tube of the character described in which the tube sections may be made of relatively soft metal, such as aluminum or the like and yet will not become deformed or worn during prolonged use of the tube.

The foregoing and other important objects of the present invention will become more apparent during the dollowing disclosure and by referring to the drawings in which:

-FIGURE 1 is a perspective view of the telescopic tube of the present invention in the form of a handle for a shovel, the latter being shown in dot-and-dash line, as it forms no part of the invention;

FIGURE 2 is a partial longitudinal section of the telescopic tube in locked position;

FIGURE 3 is a section similar to that of FIGURE 2, but showing the tube sections in unlocked position;

FIGURE 4 is a cross-section along line 44 of FIG- URE 2;

FIGURE 5 is a cross-section along line 55 of FIG- URE 2; and

FIGURE 6 is a cross-section along line 6-6 of FIG- URE 3.

Referring now more particularly to the drawings, in which like reference characters indicate like elements throughout, the telescopic tube of the invention comprises telescopically engaged outer and inner tube sections 1 and 2 respectively. Outer tube section 1 may be rigidly secured to a shovel S or any other like implement, while the outer end of inner tube section 2 may be provided with a hand grip 3 having longitudinal ribs 4 for applying a torque on tube section 2 and also for manipulating the shovel S or the like (tool.

Outer tube section 1 has a cross-sectional shape shown ice in FIGURES 4, ,5 and 6 and which consists ota plurality of equal arc portions 5 inscribed in a circle and vforming inwardly directed angularly equally spaced ribs 6. The tube section 1 is extruded so as to have substantially uniform thickness throughout its length and through its cross-sectional shape and to be of constant cross-sectional size throughout its length.

Inner tube section 2 is cylindrical with a smooth outer surface and having an outside diameter corresponding to the diameter of the circle joining the edges of the ribs 6, so as to be in slidable contact with said ribs. In FIGURE 5, the inner tube section 2 has been shown as having a slightly smaller diameter in orderto more clearly show the unlocked position of the two tube sections.

The inner end of tube section 2 is provided with angularly equally spaced longitudinally extending slits 7 defining therebetween leaves 8 which may be radially outwardly expanded to trictionally engage the ribs 6 of the outer tube section 1, and thereby adjustably lock the two tube sections.

The means for expanding and releasing the leaves 8 consist of an expander generally indicated at 9 and formed of a body having an axial through bore provided with inner threads in threaded engagement with a bolt 10 mounted co-axially of inner tube section 2 and having one end provided with an integral bushing 11 tightly titted within tube section 2 in a Zone spaced inwardly doom the slit end of the tube section 2 and if desired, additionally rigidly secured thereto by means of cross pin 12 or the like.

Bolt 10 protrudes outwardly from the opened end of tube section 2 past the leaves 8 and is riveted or punched as shown at 13 to prevent removal of the expander 9 after the latter has been assembled with the bolt. Bolt 10 has threads 14 of long pitch, such that relatively slight rotation of the bolt .10 relative to the expander 9 will result in a relatively large longitudinal displacement of the expander with respect to the inner tube section 2.

Expander 9 consists of a frusto-conical portion 15 and of an integral head 16 in the shape of a regular polygon. Portion 15 engages the leaves 8 so as to expand the same radially outwardly, the base of portion 15 having a larger diameter than the inside of tube section 2. Head 16 provides flat side faces '17 which are in slidable contact with the ribs 6 of outer tube section 1; the edges 18 formed at the junction of the fiat faces 17, provide projections engaging the recesses formed by the arc portions 5 between the ribs 6. Thus, the head 16 can slide longitudinally in outer tube section 1, but its rotation relative to said outer tube section is positively prevented by the ribs '6 engaging the flat faces 17 near the edges 18.

Preferably head 16 has six flat faces 17 being in the shape of an hexagon, and similarly the outer tube section consists of six are portions 5 with six ribs 6; thus, six zones of the outer tube 1 engage the head 16 toprevent rotation thereof. Due to the plurality of abutting surfaces there will be no Wear of the ribs -6 of outer tube section 1, even if said tube is made of a soft metal such as aluminum.

The telescopic tube is operated as -follows: The outer tube section 1 is grasped by one hand while the grip 3 of the inner tube section 2 is grasped with the other hand. In the releasing position of the expander 9, the two tube sections may be longitudinally adjusted as desired, then grip 3 is rotated for less than a quarter of a turn while holding outer tube section 1 stationary. This causes screwing of bolt 10 within expander 9, the latter being held against rotation by 'the engagement of its fiat faces '17 with ribs 6 of outer tube section 1. Inward movement or the conical portion 15 of the expander relative to the inner tube section causes engagement of the leaves 8 with the frusto-conical surface of portion 15 and expand- 3 ing of said leaves to thereby firmly and frictionally engage the ribs 6 of outer tube section 1. Thus, the two tube sections are positively locked in length adjusted position. To release the tube sections, it is only necessary to: rotate the inner tube section in the opposite direction while holding the outer tube section stationary.

It will be noted that the outer tube section fo-rms a plurality of longitudinal ribs which assist in holding the tube section 1 stationary during rotation of the grip 3. Yet the arc portions 5 form ribs with no sharp edges, and therefore said tube is comfortable to use when handling the shovel or like implement provided with the telescopic tube of the invention as a handle. Obviously, the number of circular arc portions 5 and the corresponding number of fiat :fiaces 17 of the regular polygon head 16 may be decreased or increased in accordance with the present invention. -If desired, the outer end 19 of the tube section 1 may be swaged or crimped inwardly to provide an abutment for preventing removal or the inner tube section 2.

While a preferred embodiment in accordance with the present invention has been illustrated and described, it is understood that various modifications may be resorted to without departing from the spirit and scope of the appended claims.

What we claim is:

1. A telescopic tube comprising an outer tube section and an inner tube section in telescopic engagement, said outer tube section having inner longitudially extending ribs and intervening recesses, said inner tube section having an outer cylindrical surface slidabvly engageable With said ribs and rotatable and longitudinally movable with respect to said outer tube section, the telescoped end or said inner tube section having slits defining expandable leaves therebetween, a bolt disposed coaxially of said inner tube section and having one end secured to the same in a zone spaced inwardly from said telescoped end and protruding from said leaves, an expander in threaded engagement with said bolt and consisting of a frustoconical portion having its smaller end fitting within said inner tube section and engageable with said leaves t expand the same and cause said leaves to frictionally and tightly engage said ribs in order to lock said two tube sections in adjusted position said expander further having an integral head located outside of said inner tube section and providing radial projections engageable with said recesses and ribs to prevent rotation of said expander with respect to said outer tube section and yet allow longitudinal displacement of said expander with respect to said outer tube section.

2. A telescopic tube as claimed in claim 1, wherein said outer tube section has a cross-sectional shape formed by a plurality of equal arc portions inscribed in a circle defining longitudinally extending external ribs of substantially circular cross-section at the outer surface of said outer tube section said external ribs in turn defining said inwardly directed inner ribs and intervening recesses at the inner surface of said outer tube section, said head having the shape of a regular polygon providing flat side faces the center part of which is slidable on the inner ribs of said outer tube section and the edges of which enter within said recesses.

3. A telescopic tube as claimed in claim 1, wherein said inner tube section has a smooth cylindrical surface and its outer end is provided with a hand grip.

4. A telescopic tube as claimed in claim 1, wherein the outer end of said bolt is enlarged to prevent disengagement of said expander therefrom.

References Cited in the file of this patent UNITED STATES PATENTS 2,454,989 Carlson et al Nov. 30, 1948 FOREIGN PATENTS 536,003 Germany Oct. 24, 1931 

1. A TELESCOPIC TUBE COMPRISING AN OUTER TUBE SECTION AND AN INNER SECTION IN TELESCOPIC ENGAGEMENT, SAID OUTER TUBE SECTION HAVING INNER LONGITUDIALLY EXTENDING RIBS AND INTERVENING RECESSES, SAID INNER TUBE SECTION HAVING AN OUTER CYLINDRICAL SURFACE SLIDABLY ENGAGEABLE WITH SAID RIBS AND ROTATABLE AND LONGITUDINALLY MOVABLE WITH RESPECT OT SAID OUTER TUBE SECTION, THE TELESCOPED END OF SAID INNER TUBE SECTION HAVING SLITS DEFINING EXPANDABLE LEAVES THEREBETWEEN, A BOLT DISPOSED COAXIALLY OF SAID INNER TUBE SECTION AND HAVING ONE END SECURED TO THE SAME IN A ZONE SPACED INWARDLY FROM SAID TELESCOPED END AND PROTRUDING FROM SAID LEAVES, AN EXPANDER IN THREADED ENGAGEMENT WITH SAID BOLT AND CONSISTING OF A FRUSTOCONICAL PORTION HAVING ITS SMALLER END FITTING WITHIN SAID INNER TUBE SECTION AND ENGAGEABLE WITH SAID LEAVES TO EXPAND THE SAME AND CAUSE SAID LEAVES TO FRICTIONALLY AND TIGHTLY ENGAGE SAID RIBS IN ORDER TO LOCK SAID TWO TUBE SECTIONS IN ADJUSTED POSITION SAID EXPANDER FURTHER HAVING AN INTEGRAL HEAD LOCATED OUTSIDE OF SAID INNER TUBE SECTION AND PROVIDING RADIAL PROJECTIONS ENGAGEABLE WITH SAID RECESSES AND RIBS TO PREVENT ROTATION OF SAID EXPANDER WITH RESPECT TO SAID OUTER TUBE SECTION AN YET ALLOW LONGITUDINAL DISPLACEMENT OF SAID EXPANDER WITH RESPECT TO SAID OUTER TUBE SECTION. 